Xamarin.Forms: Get native image from ImageSource

Sometimes we need to implement images in our custom renderers and as a first solution most of developers take the decision to use a string property but for me is not the better and standard way to manage image resources on Xamarin.Forms, in this blog we will take a look to a helper class that help us to manage images resource on your Xamairn.Forms renderers using a IImageSourceHandler.

There are three IImageSourceHandler helper classes:
1. ImageLoaderSourceHandler: Handle the Uri resources
2. FileImageSourceHandler: Handle the local/embed resources
3. StreamImagesourceHandler: Handle the stream image resources

The first that we need is to check what kind of source have your ImageSource property using the next code

after this, with the returned IImageSourceHandler you can call the LoadImageAsync and passing the source that you want to be native and this method will be return for you an UIImage for iOS or a Bitmap for Android

Real World Example: "HeartBeatView" Control

Now we will create an example control using the previous code, we have 4 key file
1. HeartBeatView.cs: Contains the main forms control class.
2. ImageSourceExtensions.cs: Contains the "GetNativeHandler" ImageSource extension method.
3. Android: HeartBeatViewRenderer.cs: Contains the Android custom renderer code for HeartBeatView control.
4. iOS: HeartBeatViewRenderer.cs: Contains the iOS custom renderer code for HeartBeatView control.

After this you will be able to implement the heartbeat control using your own imagesource and start/stop the "heartbeat" animation using the "IsBeating" property.

Screenshots of the example control


Entradas populares de este blog

Bluetooth Arduino + Xamarin.Android

Simple ListView with Xamarin.Forms